A mobile relay (MR) as a relay base station (a relay) that moves is considered for a mobile communication technique, and to implement the mobile relay, various techniques are considered. One operation example of the mobile relay may be to introduce the mobile relay into public transportation such as a train and a bus. The mobile relay in this case has the following features. As a first feature, as shown in FIG. 30, since a plurality of terminals (terminal a, terminal b) connected to a mobile relay 3000, i.e., terminals of passengers on board, move with the vehicle, the mobile relay 3000 collectively manages mobile control such as a handover with macro base stations (Donor eNB: DeNB) 3001, 3002 to which the mobile relay 3000 connects during the ride. Thereby there is no need for each terminal itself to perform mobile control, and therefore traffic of signaling of terminals for the mobile control can be reduced. That is, since the mobile relay 3000 can collectively manage the plurality of terminals, signaling traffic to the macro base stations can be reduced. As a second feature, content and cache stored in the mobile relay or in a server provided in a vehicle such as a train with which the terminals move together are available, whereby the frequency of accesses outside the vehicle can be reduced and external traffic by the terminals can be reduced.
To implement this, the mobile relay establishes a bearer for data (U-plane) with a gateway (GW). This operation is similar to a typical 3G terminal (UE). Control information and user data of a terminal connecting to the mobile relay are both transmitted to the GW through the bearer for data of the mobile relay.
In order to provide wireless accesses on the train to all communication operators (hereinafter this may be simply called operators) in a mobile relay provided at public transportation, use of a wireless resource and a network, or network sharing to share a wireless resource among the communication operators may be considered (see the following Patent Document 1). Referring to FIG. 31, the network sharing using the mobile relay is described below by way of a system to share both of a wireless resource and a network. That is, 3G lines are used between a MR 3100 and operator (OP) terminals (UE: User Equipment) 3101, 3102 and between the MR 3100 and a DeNB 3103, and one operator network is shared among the MR 3100 and UEs 3101 and 3102, between the MR 3100 and the DeNB 3103 and between the DeNB 3103 and a core network (CN 3104). Herein, the sharing of a 3G line is implemented by incorporating information on a plurality of operators into notification information that the MR 3100 transmits. More specifically, a plurality of PLMN IDs that are IDs indicating operators are set. Thereby, when a terminal finds an operator to which the terminal subscribes from the plurality of PLMN IDs, the terminal determines that the terminal is in the network of the operator for selection.